found: Encyclopedia of popular music, 3rd edition(listed under: Slim Harpo; born James Moore, January 11, 1924, Lobdel, Louisiana; died January 31, 1970; one of the foremost proponents of post-war rural blues; began performing under the name Harmonica Slim; acquired the name "Slim Harpo" to avoid conflict with another artist known as Harmonica Slim; singer and harmonica player)

found: Encyclopedia of the blues, 2006(listed under: Harpo, Slim; born James Moore, January 11, 1924, Lobdell, LA; died January 31, 1970, Baton Rouge, LA; guitarist, harpist, singer, composer; originally performed as Harmonica Slim, but this name already existed as a recording act so the name Slim Harpo was devised by reversing "Harmonica Slim", taking the slang term for the instrument, and adding an "O")